injector tests (with injectors still installed on engine)?
 

I'm wondering if my injectors are causing my lean codes/high fuel trim numbers. since I haven't yet found another cause, after two years of searching. I have no idea how old they are , what brand are they, or what condition they're in, but I've only had one or two misfires in two years, zero start or run problems, and other than high fuel trims, nothing to complain about.

Perhaps, before I do my forthcoming hands-on vacuum line examination and/or replacement, maybe I could test the injectors thru a diagnostic app, or with my Foxwell?

The injectors should be clean (and getting cleaner), because I've fed plenty of additives thru them, even though I don't drive the X5 much.

Just prior to taking the X5 for emissions/safety inspection last month (it passed!), I put in two cans of Liqui Moly 2007 Jectron Gasoline Fuel Injection Cleaner and drove it 30 miles (probably didn't do anything that fast, but it can't hurt).

I have already been using Lucas Oil 10576 Safeguard Ethanol Fuel Conditioner with Stabilizers every second or third fill-up, and Lucas Oil 10013 Fuel Treatment (with injector cleaners) maybe once every year (I used it regularly on all my vehicles monthly, until I recently ran the 1-gallon jug empty).

And, I always get top-tier gas (premium) at either QuikTrip or Shell, so those brands already have some injector cleaners in their formulation.

Back to possible testing: is there a test on my Foxwell NT510 Elite, that might pinpoint injector problems? like balance, or spray pulse timing, or ?? Or, on my BimmerTool Android app, I've seen an injector test listed (on their website, it says it will read injectors adjustments and
read actual and expected values for air mass, intake manifold pressure, fuel pressure, but I never tried it, as I was having problems getting the app to run properly with my OBD interfaces (both a bluetooth dongle, and a USB/OTG/FTDI cable, at various times, on various Android devices). That was over a year ago, so maybe I'll try again? I don't recall any injector testing ability on my other Android apps (Torque Pro or OBDLink).

Then there's my Windows 11, ARM64-based laptop, which I've seldom tried in my X. I installed INPA (and ISTA+, but it won't open, due to low memory), and OBDWiz on it; I've barely tested functionality of the INPA, and never tried the OBDWiz (basically a more detailed vesion of the Android OBDLink app, but for Windows), so I guess I'll hook-up my 10-amp charger/maintainer again (to keep from repeating the problems I had while testing just on battery power alone), and see what I can find.

Has anyone done injector diagnosis using any of the above methods?

Yes, I used Red Line S-1 at the beginning of this thread (post 1)

I've been going through the article. Great find!

You may be onto something here. With the car off, I disconnected the purge valve from the harness and applied 12v direct power like the guy did in the video. First 1-2 times I didn't hear a click, then next couple of times I heard the "click". Hoses look fine. The purge line to the gas tank runs under/next to the airbox, by the way.

Then I started the car and scanned things again. This is the first time I noticed the STFTs within range. Check out the first part of the scan attached.

Attachment 83717

Then I drive the car for a couple minutes and parked. The elevates STFTs stared to slowly decrease.

Drove the car back home and parked again. The elevates STFTs started to decrease again.

At this stage, I tried clamped the purge valve return line to the tank but I could not get a change in the STFTs.

I thought about removing and cleaning the valve, but at this point, I don't trust it. Going to order a new purge valve tonight.

I will be as happy as you if the purge valve was the cause.

You did what you could with injector cleaning. Usually if they are dirty enough to cause fuel trim you'll get misfires galore so I don't think it's injectors.

My foxwell only tests the injectors individually either ON/OFF or pulse for 20 secs. I am not aware of any other tests. I have an NT530.

Does it read all the codes? There should have been a code for the purge valve if that was the problem.

There was not a CEL for the purge valve.

Update:

We are getting closer.

Today, I got a new VDO/Continental MAF installed. I immediately saw an increase in the new MAF signal vs. the Chinese MAF vs. My original BMW "old' MAF. Now, the MAF shows ~4 g/s at idle vs 2.x-3.x before. Considerable difference. As expected, car feels more dynamic.

Yesterday I had some downtime and I was waiting for the new purge valve anyway, so I cleaned the existing purge valve to see if it would make a difference. I didn't see a big difference.

I still have an issue with STFT, which now has been mostly negative. At load, the STFT becomes closer to normal. You can see the STFT trend up/down at idle times. During idle, the STFT is definitely negative (running rich). I am hoping this is due to the purge valve (new one should be here sometime today) getting stuck open and/or not closing appropriately. Or maybe the car just needs to learn things and will adjust to the correct numbers over some time. After the MAF replacement, I still see the biggest improvement.

https://i.imgur.com/ack4EBp.png

https://i.imgur.com/JqJ3MO2.png

Update again:
Got the new purge valve installed. First look ... Numbers look promising. I'm going to drive it for a bit and rescan, but I do not see the typical rise/drop from the STFT at idle that I have been seeing before. Numbers a little off, but maybe car needs to harmonize.

Quick scan....

https://i.imgur.com/fy4OikS.png

Did you order an OE BMW purge valve or you gonna "add more to the soup?"

Reset fuel adaptations or it will take a few drive cycles


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